Introduce a MAINTAINERS.md file

Introduce a MAINTAINERS.md file

This file will list the current project committers and maintainers,
along with their assigned section of the code base.

Change-Id: I42c535514648b7bc91d7ec5c6460bc5bd11add03
Signed-off-by: Alexandre Montplaisir <alexmonthy@efficios.com>
Reviewed-on: https://git.eclipse.org/r/76173
Reviewed-by: Hudson CI
Reviewed-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Tested-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>